α-Melanocyte Stimulating Hormone (α-MSH)

Hormone that stimulates melanogenesis; facilitates learning and memory; affects inflammatory and immune responses and peripheral nerve regeneration.Pituitary hormone which causes darkening skin pigmentation from amphibians to humans. In mammals, it can also have behavioral effects on learning, attention, and memory.α-Melanocyte-stimulating hormone (α-MSH) acts as an anti-inflammatory agent via down regulating the production and activity of the pro-inflammatory cytokines interleukin-1 (IL-1), tumor necrosis factor (TNF)-α and IL-6 expressed in various cells of the immune system. It also controls the nitric oxide production associated with inflammation. α−MSH inhibits nuclear factor-κB (NF-κB)-dependent gene transcription and NF-κB pathway induced by TNF and other inflammatory agents. This activity of α-MSH is mediated through the production of cyclic adenosine monophosphate (cAMP) and activation of protein kinase A (PKA) enzyme. α–MSH functions as a potent therapeutics for various conditions resulted through NF-κB activation including, inflammatory diseases, human immunodeficiency virus (HIV) replication in AIDS (acquired immunodeficiency syndrome), and septic shock. α-MSH has an essential role to play in melanin production in animals. α-MSH regulates development of several skin diseases, including cutaneous inflammation and hyper-proliferative skin diseases.

[Nle4, D-Phe7]-α-melanocyte stimulating hormone is 100 times more potent than α-MSH in stimulating melanoma tyrosinase, which is a rate limiting enzyme in melanin biosynthesis and is 26 times as potent as α-MSH in S91adenylate cyclase assay. α –MSH has an essential role to play in melanin production in animals. It also regulates development of several skin diseases, including cutaneous inflammation and hyper-proliferative skin diseases.

Screening analogs of the cyclic lactam melanocortin agonist MTII led to the identification of the agoutimimetic SHU9119. This compound shares pharmacological properties with the agouti peptide in that it is a potent antagonist of the melanocortin-4 receptor and a less potent antagonist of the melanocortin-3 receptor.